Electrical regulator



y 25, 1965 H. J. HELBERG 3,185,948

ELECTRICAL REGULATOR Filed March 14, 1962 .2 Sheets-Sheet l mkg May 25, 1965 Filed March 14, 1962 H. J. HELBERG ELECTRICAL REGULATOR .2 Sheets-Sheet 2 [/2 Web/5 1/6/7131 elk/beg: MK 7245-;

United States Patent 3,185,948 ELECTRICAL REGULATOR Henry J. Helberg, West Stockbridge, Mass, assignor to General Electric Company, a corporation of New York Filed Mar. 14, 1962, Ser. No. 179,555 6 Claims. (Cl. 336-192) This invention relates to electricalregulators and more particularly to terminal boards for toroidal core sliding brushtype variable transformer regulators.

Regulators of this type typically have an autotransformer coil on the core" with a bared surface brush track engaged by a sliding brush. operated by a rotatable shaft mounted axially of the toroidal core and coil. Such a device has a minimum of at least three electrical terminals for connecting external input and output circuits to the coil and to the brush. It is desirable that these terminals be fixedly mounted on a rigid insulating terminal board so that permanent connections can be made from the coil and the brush to respective terminals. This not only facilitates making the external circuit connections necessary for the use of the device but it serves to anchor the coil and brush leads.

In accordance with this invention thereis provided a novel, simple, and inexpensive assembly for accomplishing these purposes with the use of a minimum amount of additional material. Briefly stated, the terminal board is interlocked with mating surfaces on, and clamped be tween, top and bottom core caps which in turn are anchored in place by the coil. In this manner a verystrong construction is produced.

An object of the invention is to provide a new and improved regulator.

Another object of the invention'is to provide a new and improved toroidal core sliding brush type variable transformer regulator.

A further object of this invention is to provide a new and improved terminal board mounting construction for electrical devices.

The invention will be better understood from the following description taken in connection with the accompanying drawings and-its scope will be pointed out in the appended claims.

In the drawings,

FIG. 1 is a circuit diagram of a typical sliding brush transformer regulator,

FIG. 2 is a perspective view of a complete regulator embodying the invention,

FIG. 3 is an enlarged perspective view of the core cap and terminal board subassembly for showing certain features of the invention in greater detail,

FIG. 4 is a cross-sectional view taken on line 44 of FIG. 3,

FIG. 5 is an exploded fragmentary view of the subassembly shown in FIGS. 3 and 4, and

FIG. 6 is a detailed view of the back side of the terminal board'without its terminals in place.

Referring now to the drawings and more particularly to FIG. 1, four terminals numbered 1, 2, 3 and 4 respectively are shown. Terminals 1 and 2 are typical end terminals of an auto-transformer coil 5 which is adapted to be contacted by a sliding brush 6 which is shown connected to the terminal 3. In order to increase the regulating range or versatility of the device, the terminal 4 is connected to an intermediate tap on the coil 5. An input circuit may be connected between terminal 1 and either terminal 2 or 4 and an output circuit may be connected between terminal 1 and terminal 3. By using terminal 4 as an input terminal, it will be seen that the output voltage can be made to exceed the input voltage when the brush is moved into the region between termi- 3,185,948 Patented May 25, 1965 "ice of the surface of the coil 5 indicated at 10 is bared,

that is to say, it has its insulation removed so as to form a brush track over which the brush 6 slides. The brush 6 is mounted in a suitable holder 11 in what is commonly referred to as the radiator 12 which in turn is mounted on a rotatable shaft 13 having an operating knob 14. The terminals 1, 2, 3, and 4 are shown mounted on or associated with a terminal board 14 clamped between radially extending projections 15 and 15' on the insulating core caps 8 and 8'. Actually the terminal 3 is a projection on a collector strip or lead 16 which is fastened by a screw 17 to the projection 15 on the cap 8.

Referring now to FIGS. 3, 4, and 5, the caps 8 and 8 are preferably duplicates of each other and are pieces of molded plastic insulation with an inner and outer circular rim joined by a circular web portion. They each have an integral radial extension 15 and 15' which is socketed or recessed and which receives end projections 18 on the terminal board 14. The projections 15 and 15 serve as stops or supports for the ends of the coil 5 and leave a space between certain turns of the coil into which the terminal board can be fitted and locked in place by the insertion of its end projections 18 in sockets in the projections 15 and 15'. The actual conducting or metallic terminals indicated at 19 are simple one piece U-shaped metal strips which are inserted from the back through suitable openings in the terminal board 14 so that they are securely locked in place and cannot be pulled off even when snap-on connectors are used for making external circuit connections to the device. The terminal board is preferably notched on the sides to receive the wires from the end turns of the winding and so as to hold these end turns securely in place when they are connected to terminals 1 and 2.. In order to insure proper alignment or registration of the projections 15 and 15' interfitting tongues 20 and notches 21 in the pieces 8 and 8' are provided. A threaded socket 22 and 22' is provided in the projections 15 and 15 on the duplicate core caps 8 and 8' for receiving the screw 17 as shown in FIG. 2.

While there has been shown and described a particular embodiment of the invention, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention, and therefore it is intended by the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a variable transformer, spaced pieces of solid insulation, a magnetic core within said pieces of insulation, a conducting multiple turn coil surrounding said pieces of insulation, said pieces of insulation being between said coil and said core, a space between certain turns of said coil, and a terminal board in said space, said terminal board and said pieces of insulation having interlocking surfaces anchoring said terminal board in said space.

2. In a variable transformer, duplicate spaced top and bottom pieces of solid insulation, a magnetic core disposed between said pieces of insulation, a two-layer coil of conductive wire wound thereon, said pieces of solid insulation being between said coil and said core, a space between certain turns of said coil, and a terminal board in said space, said terminal board and said pieces of insulation having interlocking projections and recesses anchoring said terminal board in said space.

3. In a variable transformer, duplicate top and bottom core caps of solid electrical insulation, a magnetic core within said core caps, a coil Wound over said core caps and magnetic core, said core caps being between said core and said coil and having a projection extending beyond said coil, a space between certain turns of said coil, and a terminal board in said space, said terminal board and said projections on said core caps having interlocking surfaces anchoring said terminal board between said core caps.

4. In combination, a toroidal container comprising.

duplicate mating coaxially disposed caps of molded plastic inuslating material, an integral socketed radially extending projection on each cap, an electrical terminal board of molded plastic insulating material having end projections sea-ted in the sockets of the projections on said caps, a wound magnetic core in said container, and a toroidal coil of wire wound on said container for clamping said caps together so as to anchor said terminal board to said container, said coil being permanently connected to terminals on said board.

5. A variable transformer as in claim 3 in which said terminal board has a plurality of perforations extending fromfront to back, and a plurality of U-shaped metal strap terminals having their legs extending through said perforations from the back to beyond the front of said terminal board with the yoke portions of said terminals pressed between the back of said terminal board and said caps of molded insulated material.

6. In a variable transformer, a toroidal magnetic core, duplicate mating molded insulation coaxially disposed core caps enclosing said core, each of said caps having an inner and an outer circular rim integrally joined by a circular web portion, each of said caps having an integral radially outwardly extending portion provided with an axially extending socket, a rim of each cap having an axially extending notch and tongue of complementary shape disposed diametrically opposite each other whereby when sa-id caps enclose said core said notches and tongues interfit in mating relation to provide angular registration of said radially outwardly extending portions, an electrical terminal board having opposite ends fitted in the sockets of said outwardly extending portions, and a toroidal coil of wire surrounding said caps and preventing their axial separation so as to lock said terminal board in position between said radially extending portions.

References Cited by the Examiner UNITED STATES PATENTS 1,815,213 7/31 Ogg 336-192 1,884,385 10/32 Thordarson 336--192 2,485,745 10/49 Koonz 336--192 X 2,976,477 3/61 Carpenter 336-148 X 2,985,857 5/61 Ellin 336148 3,025,452 3/62 Ross 336-149 X 3,087,132 4/63 Snowdon 336148 JOHN F. BURNS, Primary Examiner. 

1. IN A VARIABLE TRANSFORMER, SPACED PIECES OF SOLID INSULATION, A MAGNETIC CORE WITHIN SAID PIECES OF INSULATION, A CONDUCTING MULTIPLE TURN COIL SURROUNDING SAID PIECES OF INSULATION, SAID PIECES OF INSULATION BEING BETWEEN SAID COIL AND SAID CORE, A SPACE BETWEEN CERTAIN TURNS OF SAID COIL, AND A TERMINAL BOARD IN SAID SPACE, SAID TERMINAL BOARD AND SAID PIECES OF INSULATION HAVING 